Some things you take for granted so much you never think to mention them.
One thing I always have handy are a few zip-lock plastic bags, in case of sudden dampness. Small items such as voice recorders can be sealed from the rain in seconds.
Last night I set up some cameras, indoors. When I returned today it was raining. So much water fell from the sky I thought a sea must have evaporated somewhere. So I decided to leave the cameras and take the tapes home. Even so, it was a hundred yards to the car park and I was certain to be soaked.
That's where the zip-lock bags came in handy. I was drenched but the tapes were fine. They are now being transferred to computer, which unfortunately means playing the whole tape. There's no quick way.
Zip-lock bags; cheap, almost weightless but indispensable.